1. Field of the Invention
This invention relates to an inspection apparatus for inspecting surfaces of spheres or spherical bodies such as steel balls to detect flaws thereby screening out.
2. Description of Related Art
With conventional inspection apparatus for surfaces of spheres, for example, steel balls for use in ball bearings, it has been a common practice to inspect the spheres in air. This inspection method is advantageous in that it is easy to handle the spheres, but the surfaces of spheres must beforehand be degreased cleanly and dried. The greasy contents, if not completely degreased, remained as stain, as a result of which not only were the stained spheres culled as rejects, but also the greasy contents were accumulated at the passageway of the inspection station, and further attached to another spheres, thus being responsible for rejects.
A complete degreasing method has been therefore investigated and for example, an attempt has been made to conduct ultrasonic cleaning with an organic solvent. According to the cleaning method in the solvent, however, aside from the fact that the substance itself may be toxic or not friendly to the earth environment, an extra device for recovery of the solvent to reduce the running cost is necessitated, thus making the overall apparatus larger. Currently, the situation is improved to some degree since several less toxic and environmentally-friendly substances have been developed, and yet the circumstances still do not change seeing that the apparatus as a whole is large-sized.
In particular, the spheres made of a metal susceptible to rusting are required to be treated as quickly as possible after degreasing lest those allowed to stand for a long time in the degreased state should not be rusted. Otherwise installation of an extra air conditioning facility is neccesitated.
In order to cope with the present situation and to overcome the problems above, the invention is designed to provide an inspection apparatus or surfaces of spheres by adopting a new approach of inspecting in an oil without causing the foregoing problems with greasy staining. Accordingly, important objects of this invention are to eliminate the necessity of degreasing, to get rid of any danger of rusting even with a metal liable to rusting, to dispense with any air-conditioning even during a long-time treatment, to enable compactization, making the installation space smaller, and to make the steps of cleaning and screening continuous thereby enhancing the workability. Another object is to heighten the efficiency and accuracy of inspection of the apparatus.
The present invention for accomplishing the aforesaid objects resides in the construction of an inspection apparatus for surfaces of spheres which comprises a combination of: a supply device for supplying the spheres to be inspected; a cleaning device for the spheres so supplied; an inspection and screening mechanism for the spheres thus cleaned and delivered through a tubing; and a removal device for removing the spheres thus inspected separately according to the screening class and housing them in separate containers. And the apparatus is characterized in that the inspection and screening mechanism includes a driving roller; alignment fingers, provided upstream of the driving roller, for putting the spheres supplied in a line one by one onto the driving roller under rotation; a feeding roller for thrusting each sphere carried on the driving roller toward the rotational direction of the driving roller; a set of conical control rollers disposed to tangentially contact with the surface of the sphere thus thrusted with an outer periphery of the driving roller, a support roller, disposed adjacent to and downstream of the control rollers, for supporting the sphere; a sensor for insecting the surface of the sphere supported on the driving roller, the set of controllers, and the support roller; a discriminating gate disposed at the output side of the support roller; and an oil tank holding therein the driving roller, the feeding roller, the set of control rollers, the support roller, the sensor and the discriminating gate so that the surfaces of the spheres can be inspected in the oil thereby to discriminate and screen the spheres in terms of non-defective and defective.
According to another embodiment, the apparatus is further characterized in that the cleaning device includes a rotary disc and a fixed disc which are superposed on each other at the surface side and reverse side, respectively of the device and held in a slanting manner, the rotary disc being defined concentrically with holes for placing therein every one of the spheres in the same pitch radially and circumferentially, the fixed disc being defined partly with a cutout for delivery of the spheres therefrom; cleaning brushes provided on and in contact with the rotary disc at a predetermined position in the rotational direction thereof so that the spheres supplied in the holes can be cleaned with the cleaning brushes with the rotation of the rotary disc and the cleaned spheres can be delivered in sequence from the cutout downwardly.
According to the apparatus of this invention stated above, the spheres loaded on the supply device are supplied to the cleaning device in a definite number and then cleaned one by one in mutually discrete state by the rotation of the cleaning brushes. The cleaned spheres are transferred in a line to the screening mechanism. The inspection station of the screening mechanism is located in oil where the spheres are inspected at their surfaces one by one by means of the sensor and automatically screened between good or non-defective spheres and rejects or defective spheres.
The spheres thus screened are lifted up out of the oil, and those non-defective are coated with a rust-proof oil and then recovered into a container of the removal device while the rejects are recovered to another container.
More specifically stated, in the cleaning device constructed above, the spheres supplied quantitatively roll by their own weights thereby to enter into the holes of the rotary disc under revolution. Here, being apertured concentrically in the same pitch radially and circumferentially the spheres are guided through a chute, which is provided with guide grooves so as to adapt to the radial pitch of the spheres, into the holes. The spheres entering into the holes of the rotary disc under revolution are conveyed sequentially to the position of the brushes and cleaned, while being rotated neary one turn, with the brushes under rotation.
The cleaned spheres are withdrawn out of the cutout of the fixed disc downwardly, aligned in a line with the aid of the alignment device, and delivered in a line toward the next inspection station.
At the inspection and screening mechanism, the spheres thus traded in a line from the cleaning device are supplied, at the top of a chute, through alignment fingers for aligning the flow of spheres and feed rollers one by one to an inspection spot.
Here, the operation is conducted in the following manner: When the alignment fingers ascend, one sphere passes. And the alignment fingers revert to the original position, thus stopping another sphere next to the sphere from flowing. The sphere being carried on the driving roller is forced into the inspection spot with the aid of the feed roller revolving concentrically with the driving roller. At the inspection spot, the sphere is supported by four points of the driving roller, the set of control rollers and the support roller.
The driving roller revolves in the progress direction, whose rotation force is transmitted to the sphere and further rotates the set of control rollers making in tangential contact with the sphere. The control rollers assume a conical form and are provided, at their tops opposite to their conical sides, with gears so that their movement may be transmitted to the sphere to be inspected. The control rollers are needed to revolve lightly and silently, and to that end, the gears are of eccentric helical gears having an eccentricity of the same magnitude. The eccentricity imparts a twist to the sphere and the sphere imparted with the twist moves to the sensor, which serves, in turn, to inspect the front surface of the sphere.
After inspection, the sphere is discriminated in terms of non-defective or defective on an electric circuit, which moves the support roller so as to discharge the sphere from the inspection spot and screens out with the discriminating gate.